The objective of this research project is to find means to facilitate the study of the biogenesis of bacterial membranes and to use these means to elucidate mechanisms for the formation of membranes and regulatory functions dependent upon or affecting membrane systems. We have previously isolated mutants in four genera of bacteria that enable us to reversibly stop lipid synthesis. Using these mutants we will investigate the integration into membrane of complex systems such as those for electron transport and photosynthesis. The physiological consequences of stopping lipid synthesis will also be investigated. Cell division will be studied by means of the analysis of mutants containing nonsense mutations with respect to division functions. These will be isolated in a strain of E. coli containing a nonsense suppressor and a modifier gene that prevents suppression at high temperatures. The development of a lipid containing bacteriophage phi 6 will be studied by analyzing the morphogenetic defects in mutants that we have already isolated. These mutants are defective in development at high temperatures.